A RAPID TEST TO EVALUATE IN-VITRO SENSITIVITY OF SEPTORIA-TRITICI TO FLUTRIAFOL, USING A MICROTITRE PLATE READER

The sensitivity of Septoria tritici to the sterol biosynthesis inhibit ing fungicide flutriafol was assessed using a quick and objective tech nique based on light absorbance to measure fungal growth. Microtitre p lates were inoculated with suspensions of pycnidiospores taken directl y from single pycnidia on leaves, after which glucose peptone broth co ntaining different fungicide concentrations was added. After 10 days' incubation in the dark at 17 degrees C, growth was measured using a sp ectrophotometer at 405 nm. A dose-response curve fitted to the absorba nce data was used to estimate the fungicide concentration reducing abs orbance by one half (EC(50)) The method was precise, quick, reproducib le and objective, with substantial advantages over conventional techni ques.